For cutting steel and the like, a cermet insert, having a microstructure constituted with hard phases (hard particles) and a binding phase existing between the hard phases, has been conventionally used. Various techniques have been proposed in order to improve the efficiency of such cermet insert.
For example, Patent Document 1 described below suggests cermet alloy with high toughness in which breakage resistance is improved by determining the volume of particles, independently containing a metallic phase therein, to 10 vol % or larger of the entirety of a hard phase.
Moreover, Patent Document 2 described below proposes a cermet cutting tool whose breakage resistance is improved by dispersing particles inside of the cutting tool. The particles have a concentration distribution wherein the content ratio of Ti and W is higher in a core portion than in a peripheral portion, inside of the cutting tool.
Patent Document 1: Japanese Patent No. 2775646